From patchwork Wed Mar 30 18:55:46 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 88952 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 71C2AB6F14 for ; Thu, 31 Mar 2011 05:56:55 +1100 (EST) Received: from localhost ([127.0.0.1]:33500 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q50ZY-000297-UM for incoming@patchwork.ozlabs.org; Wed, 30 Mar 2011 14:56:53 -0400 Received: from [140.186.70.92] (port=57580 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q50YY-000242-43 for qemu-devel@nongnu.org; Wed, 30 Mar 2011 14:55:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q50YW-0004qp-Pw for qemu-devel@nongnu.org; Wed, 30 Mar 2011 14:55:49 -0400 Received: from verein.lst.de ([213.95.11.211]:59486 helo=newverein.lst.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q50YW-0004qc-LE for qemu-devel@nongnu.org; Wed, 30 Mar 2011 14:55:48 -0400 Received: by newverein.lst.de (Postfix, from userid 2407) id AF98114135; Wed, 30 Mar 2011 20:55:46 +0200 (CEST) Date: Wed, 30 Mar 2011 20:55:46 +0200 From: Christoph Hellwig To: Conor Murphy Subject: Re: [Qemu-devel] virtio-blk.c handling of i/o which is not a 512 multiple Message-ID: <20110330185546.GA26589@lst.de> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 213.95.11.211 Cc: qemu-devel@nongnu.org X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org On Wed, Mar 30, 2011 at 08:48:18AM +0000, Conor Murphy wrote: > Is there a requirement for virtio-blk guest drivers that all i/o requests are > sized in multiples of 512 bytes? Yes, like for any other block driver. Of course this should not actually crash qemu, but rather fail the request. Does the patch below give you a correct error report? Index: qemu/hw/virtio-blk.c =================================================================== --- qemu.orig/hw/virtio-blk.c 2011-03-30 20:46:10.268665534 +0200 +++ qemu/hw/virtio-blk.c 2011-03-30 20:49:45.655247322 +0200 @@ -290,6 +290,10 @@ static void virtio_blk_handle_write(Virt virtio_blk_rw_complete(req, -EIO); return; } + if (req->qiov.size % req->dev->conf->logical_block_size) { + virtio_blk_rw_complete(req, -EIO); + return; + } if (mrb->num_writes == 32) { virtio_submit_multiwrite(req->dev->bs, mrb); @@ -317,6 +321,10 @@ static void virtio_blk_handle_read(VirtI virtio_blk_rw_complete(req, -EIO); return; } + if (req->qiov.size % req->dev->conf->logical_block_size) { + virtio_blk_rw_complete(req, -EIO); + return; + } acb = bdrv_aio_readv(req->dev->bs, sector, &req->qiov, req->qiov.size / BDRV_SECTOR_SIZE,